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Articles 5131 - 5160 of 5698
Full-Text Articles in Engineering
Optimal Silo Attack Plan For The Red Integrated Strategic Offensive Plan (Risop), Richard C. Pace
Optimal Silo Attack Plan For The Red Integrated Strategic Offensive Plan (Risop), Richard C. Pace
Theses and Dissertations
The Joint Staff Directorate for Force Structure, Resources, and Assessment (J-8) sought a procedure which could be used to generate an optimal missile allocation for the silo attack portion of the Red Integrated Strategic Offensive Plan (RISOP). Their current solution procedure is a manual heuristic which is time-consuming and is not guaranteed to lead to an optimal solution. J- 8 defines an optimal solution as a feasible solution which minimizes both the flight time of the missile that impacts first and the duration of the attack. J- 8 defined several input rules which limit how missiles may be allocated. A …
A Modified Anderson Darling Goodness-Of-Fit Test For The Gamma Distribution With Unknown Scale And Location Parameters, Tamer Ozmen
Theses and Dissertations
A new modified Anderson-Darling goodness-of-fit test is introduced for the three-parameter Gamma distribution when the location parameter is found by minimum distance estimation and scale parameter by maximum likelihood estimation. Monte Carlo simulation studies were performed to calculate the critical values for A-D test when A-D statistic is minimized. These critical values are then used for testing whether a set of observations follows a Gamma distribution when the scale and location parameters axe unspecified and are estimated from the sample. Functional relationship between the critical values of A-D is also examined for each shape parameter by the variables, sample size …
The Airlift Capabilities Estimation Prototype: A Case Study In Model Validation, Randy Mccanne
The Airlift Capabilities Estimation Prototype: A Case Study In Model Validation, Randy Mccanne
Theses and Dissertations
This study investigates the application of a life cycle approach to the validation of operational models. The classic waterfall life cycle from software engineering is adapted for use on mathematical models by defining four stages of model development. Each stage is discussed in detail and examples of the output from each stage are presented. In addition, techniques are investigated for applying the proposed life cycle to existing models through the recovery of life cycle stages. The methodology is applied to a linear programming model developed for planning airlift operations to demonstrate the power of the life cycle approach to validation. …
Bradley Fighting Vehicle Gunnery: An Analysis Of Engagement Strategies For The M242 25-Mm Automatic Gun, James G. Riley
Bradley Fighting Vehicle Gunnery: An Analysis Of Engagement Strategies For The M242 25-Mm Automatic Gun, James G. Riley
Theses and Dissertations
This thesis studies various engagement strategies for the Bradley Fighting Vehicle's 25-mm automatic gun firing APDS-T ammunition against a BMP- type target. The Army currently provides only the broadest guidance for the structure of the 25-mm point target engagement which results in the employment of an assortment of strategies throughout the Bradley community. The goal of this research was to determine if a best method exists. Bradley gunnery is a complex set commander/gunner interactions which can be difficult to represent with the analytic models commonly found in the literature. A model, based on the simulation methods used by the US …
Determining Cargo Flow For Air Mobility Command's Channel Cargo System, Michael Del Rosario
Determining Cargo Flow For Air Mobility Command's Channel Cargo System, Michael Del Rosario
Theses and Dissertations
This research investigated using a multiperiod multicommodity minimal cost flow (M2MCF) formulation to model the channel cargo system of the United States Air Force's Air Mobility Command (AMC). The objective of this research was to determine how cargo should flow in the channel cargo system in order to minimize the cargo's delay enroute from its origin to its destination. This research showed the size of an M2MCF model of the channel cargo system exceeds AMC's computational capabilities. Additionally, this research describes three approaches to reduce the problem size. Because of the problem size and other modeling limitations discovered during this …
Integrating Psychological Operations Into The Joint Theater Level Simulation (Jtls), C. Matthew Pecot Iii
Integrating Psychological Operations Into The Joint Theater Level Simulation (Jtls), C. Matthew Pecot Iii
Theses and Dissertations
This thesis provides a prototype and methodology for integrating psychological operations (PSYOP) into the Joint Theater Level Simulation (JTLS) combat model. The requirement rose out of the need for aggregate-level training models to reflect the role of PSYOP so that commanders and their staffs can learn how to manage plan for, and conduct PSYOP within the context of AirLand battle doctrine. As the JTLS model currently exists, there is no representation of psychological operations whatsoever. This thesis outlines a methodology for incorporating the PSYOP analysis process (including the target audience analysis), the PSYOP product development and production process, the PSYOP …
An Analysis Of The Generalized Lambda Distribution, Robert J. Bergevin
An Analysis Of The Generalized Lambda Distribution, Robert J. Bergevin
Theses and Dissertations
The Generalized Lambda Distribution (GLD) is a four parameter function that is capable of mimicking the behavior of a wide range of probability density functions (pdfs). Unfortunately, the GLD presently cannot model every possible type of pdf. Since the reasons for this limitation are unknown, this thesis examines several potential problems in an attempt to expand the range of distributions the GLD can mimic. We first present a discussion of the behavior of the algorithm that is used to search for the appropriate GLD parameter values. In particular, we examine the effect of using an unconstrained search to find the …
A New Goodness-Of-Fit Test For The Weibull Distribution Based On Spacings, Mark C. Coppa
A New Goodness-Of-Fit Test For The Weibull Distribution Based On Spacings, Mark C. Coppa
Theses and Dissertations
The critical values for a new goodness-of-fit test based on spacings are generated for the Weibull distribution when the shape parameter is known. The critical values are used for testing whether a set of observations follow a Weibull distribution when the scale and location parameters are unknown. A Monte Carlo simulation with 10,000 iterations is used to generate the critical values for sample sizes 5(5)35 at shape parameters k equal to 0.5(0.5)1.5 and for sample sizes 5(5)20 at shape parameters k = 2.0(1.0)4.0. A Monte Carlo power study of the Z* test statistic using 5000 iterations is accomplished using nine …
The Battle Of Little Round Top: An Analysis Of Battle Alternatives Through Commercial Wargames, John J. Mcguiness
The Battle Of Little Round Top: An Analysis Of Battle Alternatives Through Commercial Wargames, John J. Mcguiness
Theses and Dissertations
This thesis examines the problem of whether one can use commercial wargames as a tool for historical research. The research examines two wargames dealing with the battle of Little Round Top: Gettysburg: The Turning Point and Thunder at the Crossroads. This research emphasized the need to analyze the wargame's structure prior to playing the game. This will avoid a possible mistake of drawing a conclusion about a particular driver in the battle which may not be from the historical situation but rather an inevitable outcome produced by the model's basic assumptions. Additionally, quantitative measures of time lines, casualty rates, and …
A Fuzzy Logic Optimal Control Law Solution To The Cmmca Tracking Problem, Randy E. Nelson
A Fuzzy Logic Optimal Control Law Solution To The Cmmca Tracking Problem, Randy E. Nelson
Theses and Dissertations
The Air Force uses the C-18 Cruise Missile Mission Control Aircraft (CMMCA) to radar track cruise missiles (CM) during test flights. Because of the complexity of the CM flight profiles, maintaining radar coverage at all times is very difficult. This thesis attempted to apply optimal control theory to construct a simulation providing 100% radar coverage. The simulation was divided into ten second intervals, and fuzzy logic was used at the start of each interval to determine the set point, i.e., that point in space where the CMMCA should be in ten seconds. The set point calculation's fuzzy logic balanced CMMCA …
Patient Scheduling And Aircraft Routing For Strategic Aeromedical Evacuation, Michael J. Loftus
Patient Scheduling And Aircraft Routing For Strategic Aeromedical Evacuation, Michael J. Loftus
Theses and Dissertations
The objective of this study is to develop an approach that would assign patients to aeromedical evacuation aircraft and route each aircraft to a single CONUS airport. The goal is to minimize total patient wait time. A heuristic algorithm is developed which exploits the structure of the problem. The first subproblem solved is the assignment of aircraft to airports. This subproblem is solved using integer programming and the results are input into the second subproblem. The second subproblem is the patient to aircraft assignment problem. This subproblem minimizes patient wait time and is solved using network flow programming. The two …
An Analysis Of Tactical Airlifter Characteristics And Their Impact On Theater Airlift System Performance, John J. Koger
An Analysis Of Tactical Airlifter Characteristics And Their Impact On Theater Airlift System Performance, John J. Koger
Theses and Dissertations
This study used computer simulation and Response Surface Technology to determine what tactical airlifter characteristics most impact theater airlift system performance in a Southwest Asia (SWA) scenario. Some Aircraft characteristics were grouped into functional sets, while others were considered individually. After screening one characteristic, reliability, with a two-level factorial experiment, a Box-Behnken design was used to estimate second-order metamodels. A stepwise regression procedure indicated that, if attrition rates are ignored, airlift system performance is most impacted by the aircraft's size, survivability, cruise speed, and ability to operate on short fields. The SWA scenario used in this study covers a large …
Estimating Test Range Capacity, Paul A. Mcdaniel
Estimating Test Range Capacity, Paul A. Mcdaniel
Theses and Dissertations
The main focus of this thesis effort was to develop a means to estimate the capacity of the test range complex at Eglin AFB, Florida. For the purposes of this study, test range capacity was defined as the maximum number of missions, of a given set, that could possibly be supported by range resources on any given day. In trying to determine this number, the complexities of the overall multi-resource constrained scheduling problem dictated a more practical approach be taken in modeling the allocation process of range resources to test missions. Therefore, a series of three single-resource, 0-1 integer programming …
Hoph Bifurcation In Viscous, Low Speed Flows About An Airfoil With Structural Coupling, Mark J. Lutton
Hoph Bifurcation In Viscous, Low Speed Flows About An Airfoil With Structural Coupling, Mark J. Lutton
Theses and Dissertations
The locations of Hopf bifurcation points associated with the viscous, incompressible flow about a NACA 0012 airfoil with structural coupling are computed for very low Reynolds numbers (<2000). A semi-implicit, first-order-accurate time integration algorithm is employed to solve the stream function-vorticity form of the Navier-Stokes equations. The formulation models the inclusion of simple structural elements affixed to the airfoil and captures the resulting airfoil motion. The equations describing the airfoil motion are integrated in time using a fourth-order Runge-Kutta algorithm. The dissertation is divided into two parts. In part one, numerical experiments are performed in the laminar regime to determine if the structural model of the airfoil has an effect upon the location of the Hopf bifurcation point when compared with the fixed airfoil. Results are reported for a variety of structural characteristics, including variations of torsional and linear spring constants, inertial properties, structural coupling, and structural damping. The structure of the solution space is explored by means of phase plots. In part two, the Baldwin-Lomax turbulence model is implemented to model turbulent flow. A numerical effort is made to predict the onset of unsteady flow.
Design And Performance Evaluation Of A Gas Chromatograph Micromachined In A Single Crystal Silicon Substrate, Rocky R. Reston
Design And Performance Evaluation Of A Gas Chromatograph Micromachined In A Single Crystal Silicon Substrate, Rocky R. Reston
Theses and Dissertations
This investigation designed and developed a miniature gas chromatograph (GC) using silicon micromachining techniques. The GC is composed of a miniature sample injector (10 µl sample loop); a 0.9 m long, rectangular-shaped (300 µm width and 10 micrometers height) capillary column coated with a 0.2 µm thick copper phthalocyanine (CuPc) stationary phase; and a dual-detector scheme incorporating a CuPc-coated chemiresistor and a 125 µm diameter thermal conductivity detector bead. Micromachining was employed to fabricate the sample injector interface, the GC column, and the dual-detector cavity. A novel processing technique was developed to sublime the CuPc stationary phase coating on the …
An Investigation Of Graphite Peek Composite Under Compression With A Centrally Located Circular Discontinuity, Benjamin Wham Ii
An Investigation Of Graphite Peek Composite Under Compression With A Centrally Located Circular Discontinuity, Benjamin Wham Ii
Theses and Dissertations
The purpose of this thesis was to determine (both experimentally and analytically) the initiation and progression of failure, stress-strain response, and the failure loads of Graphite/Polyetheretherketone (Gr/PEEK) laminates, incorporating a centrally located circular discontinuity, loading in axial compression at room temperature. The laminates studied were (0°)16,(90°)16, (0°/90°)4S, (± 45°)4S, and (0°/±45°/90°)2S. The specimens were loaded within a Boeing Open Hole Compression Fixture. The micromechanical failure modes were identified using a Scanning Electron Microscope. The analytical progression of failure was predicted using a nonlinear finite element code developed by Dr. R.S. …
Design Of A Hardware Discrete Event Simulation Coprocessor, David W. Daniel
Design Of A Hardware Discrete Event Simulation Coprocessor, David W. Daniel
Theses and Dissertations
A hardware discrete event simulation (DES) coprocessor was designed to eliminate synchronization overhead as a possible bottleneck. The target architecture is an eight node Intel iPSC/2 Hypercube, but this design has application to future CPU designs that wish to incorporate on-chip architectural features to better support parallel processor synchronization. A structural description of a general-purpose DES hardware coprocessor is given with approximately 90 percent of the components written at the gate level. The remaining components use low-level behavioral descriptions. While the DES coprocessor microcode implements the Chandy-Misra protocol, general-purpose support for a wide-range of protocols was a primary hardware design …
Rendering The Out-The-Window View For The Afit Virtual Cockpit, W. Dean Mccarty
Rendering The Out-The-Window View For The Afit Virtual Cockpit, W. Dean Mccarty
Theses and Dissertations
The Air Force Institute of Technology (AFIT) is developing a distributed interactive flight simulator, the Virtual Cockpit, using commercial graphics workstations and helmet mounted displays. The Virtual Cockpit communicates with other simulators via local and long-haul networks using the SIMNET protocol. The work reported in this thesis focuses on developing the terrain database for the synthetic environment and on rendering the pilot's view of the database. There are many different file formats for describing 3- dimensional geometric polygonal objects. An analysis of three formats, AFIT GEOM, the Naval Postgraduate School (NPS) DRP, and Software Systems' Flight, is presented. Each file …
Afitbunki: A Modified Iterative Code To Unfold Neutron Spectra From Bonner Sphere Detector Data, Sean C. Miller
Afitbunki: A Modified Iterative Code To Unfold Neutron Spectra From Bonner Sphere Detector Data, Sean C. Miller
Theses and Dissertations
The neutron spectrum unfolding code BUNKI, developed at the Naval Research Laboratory in 1983, was modified to incorporate a finer energy group structure, seven initial-guess spectra, and new dose conversion factors. The modified code, AFITBUNKI, unfolds spectra into 54 energy groups between 10-7 and 14.92 MeV. The code calculates fluence, absorbed dose, percent of effective dose equivalent, and percent of ambient dose equivalent as a function of neutron energy. Additionally, AFITBUNKI calculates total energy-integrated fluence (Φ), absorbed dose (D), dose equivalent (H), effective quality factor (Q), ambient dose (D*), both ICRP Publication 26- and ICRP Publication 60-based ambient dose …
A Statistical Analysis Of Terrorism And Instability In Latin America, Juan A. Hurtado
A Statistical Analysis Of Terrorism And Instability In Latin America, Juan A. Hurtado
Theses and Dissertations
In this research the effect of socioeconomic factors on terrorism and government instability in Latin America are studied. A commonly held opinion is that terrorism and instability are caused by repressive conditions. The objective of this research was to generate a methodology to forecast terrorism and instability given certain socioeconomic indicators. This methodology was generated for individual countries, two groups of countries, and a composite developing country. A set of 28 socioeconomic factors were evaluated and reduced based on correlation analysis. Patterns of terrorism and instability were investigated through data analysis and factor analysis. Multiple regression was used to develop …
Spartan Ii: An Instructional High Resolution Land Combat Model, Edwin H. Harris Jr.
Spartan Ii: An Instructional High Resolution Land Combat Model, Edwin H. Harris Jr.
Theses and Dissertations
This project improved SPARTAN, a high resolution land combat model demonstrator. SPARTAN was originally developed as a hands-on trainer for land combat modeling students because there were no models specifically designed to teach the analysts how the models function. SPARTAN is built to demonstrate the techniques used in the current generation of US Army high resolution models. Like the original, the model is primarily a small scale attrition (both direct and indirect fire) model. The model represents 12 soldiers involved in the following processes: target search, target selection, direct fire engagement, indirect fire engagement, movement, reaction to fire, obstacle breaching, …
Including Maximum Sustained Wind Speed In A Time Series Model To Forecast Hurricane Movement, Timothy B. Mott
Including Maximum Sustained Wind Speed In A Time Series Model To Forecast Hurricane Movement, Timothy B. Mott
Theses and Dissertations
Techniques for applying time series fundamentals to forecasting hurricane movement are thoroughly examined in this research. The objectives are: (1) to modify Dr. Thomas Curry's threshold autoregressive time series model to improve its ability to forecast hurricane movement, (2) to forecast the maximum sustained wind speed for a hurricane, and (3) to identify if wind speed should be included as an explanatory variable to aid in forecasting hurricane movement. Eleven different models to predict the latitude, longitude and maximum sustained wind speed are compared and contrasted with Curry's bivariate time series model. The results showed the modifications allow significant forecasting …
Automating The Satellite Range Scheduling Process, Timothy D. Gooley
Automating The Satellite Range Scheduling Process, Timothy D. Gooley
Theses and Dissertations
Satellite range scheduling is a complex problem that involves scheduling satellite supports in which a satellite and a specific remote tracking station are assigned a time window during which they communicate with each other. As the number and complexity of satellite supports continue to increase, more pressure is placed on the current manual system to efficiently generate a schedule. The objective of this research was to develop a methodology that will automate the generation of the initial 24 hour schedule. The goal of the algorithm developed was to schedule as many conflict free supports as possible. A two phased approach …
A Generalized Simulation Model For A Typical Medical Treatment Facility Obstetrical Unit, Annette M. Stephens
A Generalized Simulation Model For A Typical Medical Treatment Facility Obstetrical Unit, Annette M. Stephens
Theses and Dissertations
The purpose of this research was to develop a decision support tool for users at Air Force Medical Treatment Facility obstetrical (OB) units. The immediate needs of the generalized simulation model contained in this research provide obstetrical wards with the capability to identify unit effectiveness as well as the ability to predict future performance. As a result of this model, decision-makers will now have access to information on system performance as well as insight into the effects of changing conditions. This model was formulated with the flexibility to be adapted to OB wards at regional and local hospitals throughout the …
Modified Goodness-Of-Fit Tests For The Weibull Distribution, Erol Yucel
Modified Goodness-Of-Fit Tests For The Weibull Distribution, Erol Yucel
Theses and Dissertations
This research will produce a new modified Anderson-Darling and W* goodness of fit statistics for the three parameter Weibull Distribution when all parameters unknown and estimated by Maximum Likelihood-Minimum Distance combination. The critical values for each statistic, sample size and a levels 0. 20, 0.15, 0.10, 0.05 and 0.01 are produced. The Monte Carlo Simulation used 5000 repetitions for sample sizes of 10, 15, 20, 25, 30, 40, and 50 with the Weibull shape equals to 3, scale equals to 4 and location equals to 10. The power study is made for the same sizes as above with the hypothesized …
An Analysis Of The Ability Of Commercial Wargames To Fulfill The Education Requirements Of The Air Force Wargaming Center, Scott Goehring
An Analysis Of The Ability Of Commercial Wargames To Fulfill The Education Requirements Of The Air Force Wargaming Center, Scott Goehring
Theses and Dissertations
It has been the contention of some that current commercial wargames could possibly fulfill the education requirements addressed by the Air Force Wargaming Center. The Wargaming Center, lacking the opportunity to conduct a thorough, in-house analysis of these commercial wargames, requested an independent evaluation be performed. This thesis identifies potential commercial wargames and provides an analysis of those wargames to determine their ability to educate senior military officers in the application of aerospace power. In addition, this thesis establishes a set of Measures of Effectiveness (MOEs) against which future wargames can be easily evaluated. The MOEs were developed from the …
Models For The Optimization Of Air Refueling Missions, Clayton H. Pflieger
Models For The Optimization Of Air Refueling Missions, Clayton H. Pflieger
Theses and Dissertations
This research follows A. Yamani's work on the problem of minimizing total fuel costs for airlift missions that require in-flight refueling. Yamani's major assumptions were removed and the resulting enhanced formulation was applied the the original problem and the related problem of maximizing allowable cabin load. This optimization is accomplished selecting the rendezvous point and initial fuel for each aircraft. The formulation considers a C-141B airlifter refueled once by a KC-135E tanker. Flight is assumed to be at constant altitude and follow great-circle routes. The fuel costs of climb and cruise flight are modeled as functions of gross weight, while …
The Integration Of Tanker Aircraft Into Aslar, John S. Stieven
The Integration Of Tanker Aircraft Into Aslar, John S. Stieven
Theses and Dissertations
The purpose of this study was to analyze the proposed addition of heavy KC-135 tanker aircraft to the United States Air Force Aircraft Surge Launch and Recovery (ASLAR) instrument approach system. The Air Force Communications Command, which oversees ASLAR operations, will use these results to determine if KC-135 aircraft should be permitted to fly ASLAR approaches. A SIMSCRIPT II.5 animated simulation model was developed to simulate the Runway 26 approach at Seymour Johnson Air Force Base under a variety of wind conditions. This model was expanded to show the feasibility of KC-135s flying ASLAR approaches and to determine proper controller …
An Empirical Evaluation Of Five Circular Error Probable Estimation Techniques And A Method For Improving Them, William L. Tongue
An Empirical Evaluation Of Five Circular Error Probable Estimation Techniques And A Method For Improving Them, William L. Tongue
Theses and Dissertations
This study compared five CEP estimation techniques under the assumption that the crossrange and downrange miss distances of the sample data follow a bivariate normal distribution. The analysis determined the sensitivities of these models to changes in sample size, bias, correlation, and ellipticity in terms of three measures of effectiveness: Mean relative error (RE), variance of RE, and mean squared error (MSE) of RE. In general, it was found that sample size was the most significant parameter in determining the best CEP method. Mean RE provided a 'strong' distinction between estimators, while variance and MSE provided 'weak' distinctions between estimators. …
Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr.
Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr.
Theses and Dissertations
The Air Force Institute of Technology is continuing research in the Virtual Cockpit. The Virtual Cockpit makes use of high performance graphics workstations, Virtual Environment technology, and Distributed Interactive Simulation network protocols to create a flight simulator based on the capabilities of the McDonnell Douglas F-15E Strike Eagle. The work presented in this thesis focuses on the design and implementation issues for integrating a weapons delivery capability. Weapons simulated include: RADAR and IR guided air- to-air missiles, gravity and precision guided bombs, and a 20mm cannon. Virtual Environment displays used include: color NTSC and monochrome high resolution helmet mounted displays …